I'm playing Doom 2 on Ultra Violence no cheats just trying to finish the game, a thing I have never done in my childhood, I only played with cheats and it was hard enough for me to just find the Exit.

The thing is... there's a TON of monsters, big ones that need tons of ammunition to take down and I have no ammo!

Things started to go down hill on Traps and Tricks map, after that I have killed a lot with the chainsaw but they just keep coming and not every monster is "chainsaw-friendly" specially those with rocket launcher hands.

I almost never miss a shoot so I'm using it efficiently I believe.

I'm thinking about using cheat just once to get some ammo... How I'm supposed to even play without ammo.

I finished The Ultimate Doom all episodes on UV one save per level that was a challenge but this now is no fair...

Actually, all maps can be completed with a so-called "pistol start". Yes, Map 10 is challenging, especially because there are multiple alternative paths available. But it can be completed with some path planning and careful playing. Go after the easier enemies first (without waking up the tougher enemies, if possible), gather up your ammo and other resources, then go after the bigger enemies. Also, continue doing what you're doing to conserve ammo - when possible use chainsaw & berserk fists, pistol instead of chaingun, shotgun instead of super shotgun.

Alternatively, periodically save your games, like you did with Ultimate DooM.

Tricks and Traps is one of my goto maps if I just feel like a quick blast of nice, varied but not too long Doom action. I've always found that one to be very well balanced ammo, health and monster-wise.

To conserve ammo, don't forget to use infighting and remember that the chainsaw can be very effective against some enemies (particularly demons). If you've picked up a berserk pack on a map, even once the red haze has faded you still have the mega-punch damage until you exit the level so that can be useful too.

Hello, perhaps this can be a redundant tip, but there it goes anyway...

NEVER finish a level without getting most of dropped ammunition. Once you kill all enemies, spend some time to re-explore the map for some forgotten ammo or weapons. Usually there is a lot of ammo available on each level, but one of the most common - and sometimes fatal - errors from beginner players is going too soon to the exit and leaving the map without replenishing their ammo, and sometimes even health. So, I recommend to take your time and get all you need before advancing to the next level if possible.